JP2005284508A - Welding robot system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that much labor is required for inputting data, welding output and wire feeding quantity based on teaching data can not be obtained because a practical welding output is changed in accordance with a condition and the accuracy of calculated welding process information is deteriorated in a conventional simulation method to be used as a method for obtaining welding process information. <P>SOLUTION: The system is constituted so as to acquire welding data from a welding machine 4 by a robot controller 3 by connecting the welding machine 4 to the robot controller 3 by serial communication 61, 62, eliminate the necessity of data input, transmit data concerned with practical welding output obtained by practically driving the robot 2 from the welding machine 4 to the robot controller 3, calculate a correction value by welding process information calculated by the real welding data and the teaching data, and calculate more accurate welding process information by the correction value at the time of another welding process teaching next time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a welding robot system in which a teaching playback type robot and a welding machine equipped with a wire feed control means for feedback-controlling the speed of a servo motor are combined.

  Conventionally, when a welding robot is introduced, it is necessary to make a production plan. Information necessary for making the production plan includes information such as tact time and welding cost.

  In order to know such welding costs, it was necessary to obtain welding process information such as the amount of wire and gas used and the amount of power consumption. As a method of obtaining such welding process information, a method of performing simulation by performing off-line teaching has been proposed (see, for example, Patent Document 1).

According to this method, teaching work can be performed using a robot displayed in the CRT of the simulation apparatus, and welding process information such as wire and gas usage can be obtained from information and teaching data relating to the robot inputted in advance. was there.
Japanese Patent Laid-Open No. 04-137110

  However, in the method based on the simulation, it takes time and effort to input data of a robot and a welding machine that are actually used in a simulation computer.

In addition, since the actual welding output changes depending on conditions such as the posture of the robot and the arc length, there is a problem in the accuracy of the calculated welding process information because the welding output and the wire feed amount do not match the teaching data.
An object of this invention is to provide the welding robot system which can solve the said subject.

  In order to achieve the above object, the present invention registers a welding condition at the time of teaching and teaches a teaching playback teaching type robot having means for transmitting the welding condition to a welding machine, and a wire transmission for feedback controlling the speed of a servo motor. When receiving the welding condition, a welding machine having means for transmitting wire feeding speed command data corresponding to the welding condition to the robot, teaching data and the wire feeding speed command data transmitted from the welding machine Means for calculating welding process information and means for displaying a calculation result by the means for calculating welding process information are provided.

  In this way, by connecting the welding machine and the robot control device directly via serial communication, the robot control device can directly acquire welding data corresponding to the welding conditions input at the time of teaching from the welding machine. No data input to the computer is required, and the data related to the actual welding output obtained by actually operating the welding robot is transmitted to the robot controller by the welding machine, and calculated from the actual welding data and teaching data. The correction value is calculated based on the welding process information, and the next time another teaching process is taught, the correction value can be used to calculate the welding process information with higher accuracy.

  As described above, according to the welding robot system of the present invention, the operator simply registers the welding site and welding conditions at the time of teaching, and the welding cost in the welding process is displayed on the teach pendant display unit attached to the robot controller. Since welding process information such as the welding wire, gas consumption, and power consumption required for the calculation is displayed, it is possible to easily make a production plan when introducing the welding robot.

  Further, accurate welding process information can be obtained by obtaining a correction value of the welding process information during actual operation of the welding robot and correcting the welding process information calculated at the time of teaching based on the correction value.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a welding robot system according to an embodiment of the present invention.

  In FIG. 1, the welding torch 1 is supported by the arm 21 of the robot 2, and the robot 2 is controlled by the robot controller 3 to move the tip of the welding torch at the tip of the arm 21 along the welding line of the workpiece 9. I am doing so.

  The robot 2 is a teaching playback teaching type robot, and memorizes the movement trajectory and movement speed of the arm 21 by actually moving the arm according to the movement trajectory. At the same time, the designation of each welded part on the movement locus and the welding conditions for each welded part are also stored. The welding conditions are a welding current, a welding voltage, and the like.

  A wire feeding device 8 for supplying a wire to the welding torch 1 is attached in the middle of the arm of the robot 2, and the wire feeding device 8 is rotated by a servo motor 81 whose speed is feedback controlled by the wire feeding control device 5. Driven, the welding wire 7 is fed from the tip of the welding torch 1 toward the workpiece 9 at a predetermined speed.

  The robot control device 3 and the welding machine 4, and the welding machine 4 and the wire feed control device 5 are connected by serial communications 61 and 62, respectively, and exchange of signals is performed by communication. When performing automatic welding by a robot, welding condition command data is transmitted from the robot control device 3 to the welding machine 4 via the serial communication 61, and the welding machine 4 is instructed between the welding torch 1 and the workpiece 9. Is applied to cause arc discharge between the tip of the welding wire 7 and the workpiece A to perform welding. At the same time, the wire feed speed command data corresponding to the welding condition data is transmitted to the wire feed control device 5 by the serial communication 62, and the servo motor 81 of the wire feed device 8 is transmitted at the command speed specified by the wire feed speed command data. Is controlled to feed out the welding wire 7.

  At the same time, the actual arc current and arc voltage are measured by an ammeter and a voltmeter inside the welding machine 4 (both not shown) and transmitted to the robot controller 3 by serial communication 61 together with actual wire feed speed data. And stored as welding process information calculation data during actual operation.

  Next, a case where teaching to weld a certain part of the work piece 9 will be described.

As described above, simultaneously with the registration of the movement trajectory of the robot arm 21, designation of each welding site and registration of the welding conditions for each welding site are performed. This registration operation is performed by the teach pendant 31 attached to the robot control device 3.

  When this welding condition is registered at the time of teaching, the welding condition data is transmitted to the welding machine 4 connected to the robot controller 3 by the serial communication 61, and the wire feed speed command data corresponding to this welding condition data is the same. The data is transmitted from the welding machine 4 to the robot control device 3 by serial communication 61.

  The robot controller 3 further determines the amount of wire used in welding at the welding site based on the welding time calculated from the wire feed speed command data and the teaching data such as the length of the welding site and the welding speed. From the welding condition data such as current and welding voltage, the power consumption consumed by welding at this welded part is calculated.

  Further, the amount of gas used is calculated based on the welding gas time calculated from the shield gas flow rate and the teaching data input in advance with the teach pendant 31.

  The calculated wire usage, power consumption, and gas usage are calculated for each teaching of each welding site, and when there are a plurality of welding sites, they are accumulated each time teaching is registered, and the teaching associated with the robot controller 3 is added. It is displayed on the display part of the bendant 31.

  FIG. 2 shows a display example on the display unit of the teach pendant 31.

  The wire usage, power consumption, and gas usage obtained in this way become welding process information necessary for production planning when a welding robot is introduced.

  However, when the teaching program is actually executed and automatic welding by a robot is performed, there are many cases where the output does not match the welding conditions instructed at the time of teaching.

  That is, the welding process information obtained from the welding condition command data and the teaching data is the welding process information obtained from the actual welding output data obtained when the automatic welding is actually executed by the robot according to the teaching program. It does not match.

  Therefore, in the welding robot system of the present embodiment, in order to increase the accuracy of the welding process information calculated at the time of teaching, the taught program is executed, and the actual operation calculated when automatic welding is actually performed by the robot is performed. Find the difference between the welding process information and the welding process information calculated at the time of teaching, record the value as a correction value corresponding to the welding conditions, and respond to the welding conditions when teaching another welding site from the next time. By performing the correction using the corrected value, highly accurate welding process information is calculated.

  This makes it possible for an operator to accurately grasp welding process information such as the amount of wire used and the amount of gas used for each welding process before and immediately after the actual operation of the welding robot. In addition, it is possible to accurately grasp the maintenance time such as the wire and gas replacement time.

  According to the welding robot system of the present invention, it is possible to easily make a production plan when introducing the welding robot, which is useful when using the welding robot.

Overall configuration diagram showing an embodiment of the present invention The figure which shows the example of a display of the teaching vendor display part in the embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding torch 2 Robot 21 Robot arm 3 Robot controller 31 Teaching bendant 4 Welding machine 5 Wire feed controller 61 Serial communication (between robot controller and welder)
62 Serial communication (between welding machine and wire feed controller)
7 Welding wire 8 Wire feeding device 81 Servo motor 9 Workpiece

Claims (4)

A teaching playback teaching type robot having means for registering welding conditions at the time of teaching and transmitting the welding conditions to a welding machine, wire feed control means for feedback-controlling the speed of a servo motor, and receiving the welding conditions A welding machine having means for sending wire feed speed command data corresponding to the conditions to the robot, means for calculating welding process information from the teaching data and the wire feed speed command data sent from the welding machine, and a welding process A welding robot system provided with means for displaying a calculation result by means for calculating information. 2. The welding according to claim 1, wherein means for transmitting welding condition data to the welding machine at the time of teaching and means for transmitting a wire feed speed command data corresponding to the welding condition by the welding machine receiving the welding condition data are serial communications. Robot system. The means for calculating the welding process information from the teaching data and the wire feed speed command data transmitted from the welding machine is calculated when the welding process information calculated from the teaching data is actually operated by welding the robot. The welding robot system according to claim 1 or 2, wherein the correction is performed by a correction value obtained from welding process information. The welding robot system according to any one of claims 1 to 3, wherein the means for displaying the calculation result by the means for calculating the welding process information is a display unit of a teaching bendant of the robot.